Burner



Patented Dec. 3, 1935 UNITED STATES PATENT OFFICE BURNER necticut Application August 4, 1930, Serial No. 473,022

4 Claims,

This invention relates to burners and more particularly though not exclusively towhat are commonly termed combustion tube burners. The latter are usually provided with one or more combustion chambers having perforated tubular walls through which air enters to mix with fuel vapor ascending from a fuel space at the bottom of the chamber, the mixture being burned in the combustion chamber and a blue flame issuing from the upper open end thereof. Such burners are commonly employed in connection with a single fuel-supply source such as oil or other liquid fuel which is supplied to or has connection with a fuel groove or trough immediately beneath the combustion chamber.

The objects of the invention among other things are to improve the construction of burners of this type, increase their utility by making them adaptable to a wider range of service and to decrease the starting interval or period required for preheating when employed with liquid fuel.

These and other objects of the invention will be best understood by reference to the following description when taken in connection with the accompanying illustration showing one specific embodiment thereof, while its scope will be more particularly pointed out in the appended claims.

In the illustrated embodiment of the invention, the burner is so constructed that it will operate with complete eifectiveness for either long or short intervals. from a supply of either liquid fuel or gaseous fuel, and the connectionsare such, that either liquid or gaseous fuel may be supplied at will so that the burner may be operated exclusively from a source of liquid fuel supply or from a source of gaseous fuel supply, or its operations at onetime when supplied with gaseous fuel may be followed without interruption by its operation with liquid fuel, or vice versa.

The ordinary combustion tube burner, when supplied solely with liquid fuel, has certain disadvantages which limit its field of usefulness.

In starting a burner of this type from a cold con-,

ditionit is necessary to pre-heat the burner walls before finally turning on the full continuing supply of the liquid fuel so that some vaporization of the fuel will take place when it reaches the fuel space and the rising vapor ignite with the incoming air in the combustion chamber.

One. common method of pre-heating is to provide the fuel groove with an asbestos or other Wick, which is first saturated with oil or other priming fluid and then lighted by a taper. After an interval of pre-heating suflicient to cause a vaporization of a portion of the liquid fuel reaching the fuel groove, the supply is then turned on. As the temperature rises, the walls of. the groove and adjacent passages become more highly heated and an increasingly greater proportion of the fuel reaches the groove in vaporized form and finally, 5 after the lapse of a substantial interval, the fuel reaching the fuel space or spaces is completely vaporized and an intensely hot blue flame results.

The prolonged interval required for the preheating before the burner can be brought to its full heating capacity, which may be termed the starting interval, is a serious drawback to the more general use of this type of burner. Due also to the fact that the oil or other fuel is delivered in liquid form and must be vaporized by the heated surrounding Walls of the burner before it can be ignited in the combustion chamber, the heating effect ofv a burner of given size is limited and, while it may be ample for ordinary purposes, if an especial occasion arises calling for a more intense heat, the burner cannot be forced beyond a given point by merely increasing the rate with which liquid fuel is supplied.

In the described embodiment of the invention, if it is desired to operate the burner with liquid fuel, the starting interval may be out down to a relatively short period by first turning on and igniting the gas from the source of gas supply which will immediately develop the full heating capacity of the burner and will quickly raise the temperature of the burner walls to a point sufiicient to fully vaporize the oil. Accordingly the latter, without the long delay heretofore necessary, may be quickly turned on and the gas shut off, almost immediately reaching the full oil-heating capacity of the burner under the supply of liquid fuel, thereby eliminating in large measure the disadvantage due to a prolonged starting interval.

On the other hand, where it is desired usually to operate the burner under liquid fuel but at times to operate it under conditions of more intense heat than could be obtained by liquid fuel, the latter may be shut off and the gas turned on to force the burner beyond its liquid-fuel heating capacity and to give whatever degree of flame may be called for.

The construction of the burner which qualifies it to burn either type of fuel adapts it to a wide range of conditions. If gas is readily avail- 5O able and relatively economical it may be employed primarily with gas, and liquid fuel may be drawn from a source of liquid fuel supply only on those occasions when, as often happens, the gas supply may fail or be inadequate. If, as is usually the case, liquid fuel is more economical than gas, the burner may be primarily operated from the source of liquid fuel and operated with gas only for ore-heating or when the liquid fuel supply is depleted or' not available, or when a special occasion arises for forcing the burner beyond a heating capacity which is obtainable from the liquid fuel. On the other hand, the

burner may be operated at will exclusively by.

liquid fuel or exclusively with gas, as circumstances may demand.

Referring to the drawing1- Figure 1 is a plan view of a burner embodying one form of the invention, the cover plates for the air spaces or chambers being partly broken away to better show the construction of the base member; 7

Fig. 2 is a vertical sectional elevation on the line 2-4 of Fig. l, and

Fig. 3 is a fragmentary view comprising a sectional elevation on the line 3-3 of Fig. 1.

Referring to the drawing (Figs. 1, 2 and 3) and to the embodiment of the invention which is submitted for illustrative purposes, the burner is provided with a base member I having an outer annular plate 3 and an inner annular concentric plate 5, connected one to the other by a series of webs I, herein four in number, and providing for an annular air admission space 9 between the plates'.

The inner plate 5 is provided with a central air admission opening I I surrounded by an upturned ring-like flange I3, the outer edge of the inner plate 5 having also an upturned ring-like flange I5 spaced from but concentric with the flange I3. The flanges I3 and 55, together with the bottom plate 5, form a relatively wide annular compartment or channel, on the bottom of which there is provided a raised annular lip I'I separating the compartment into an outer fuel space defined by the groove I9 and an inner vaporizing space 2|, to which latter liquid fuel, such as oil, may be delivered by the pipe connection 2| through the opening 23 in the bottom of the plate. The an nular lip I'I constitutes a bafiie Which normally prevents the direct flow of the fuel in liquid form from the opening 23 to the fuel groove I9, the travel thereto of the vaporized liquid fuel taking place, however, without hindrance over the top of the raised lip. The bottom of the vaporizing space Within the annular lip constitutes a flow plate over which any liquid fuel entering the burner must flow, and by which, when the burner is heated, it is readily vaporized.

The outer annular plate 3 is also constructed to present an outer fuel groove 25 formed between upright spaced annular flanges 2'I and 29 on said plate. Connected to one of the fuel grooves or spaces, and herein through the outside flange Zl to the. outer fuel groove 25, is a pipe connection 3I for supplying gaseous fuel to the burner. The outer fuel groove 25' is connected to the inner fuel groove I9 by means of supply ducts 33 (Fig. 3) formed in the webs I, so that free circulation takes place throughout both fuel grooves of either vaporized liquid fuel supplied through the pipe 28- or gaseous fuel supplied through the pipe 35. e e

The top of the vaporizing chamber is closed except for the direct escape of vaporized fuel to the fuel space I9 by a removable annular cover plate 35, the under side of which is grooved to seat on the upper edge of the flange I3 with a preferably close fit. The walls of the cover plate extend outwardly, and herein also downwardly,

over the vaporizing compartment and the annular lip, but are spaced vertically from the latter to provide an annular passage from the vaporizing compartment to the fuel space, so that any vaporized fuel may pass directly over the lip between the latter and the cover plate and into the fuel space I9.

Above the lip I! the cover plate is provided with an upturned flange 31, within which there is supported a perforated sheet metal cylinder 39.

A similar but larger concentric cylinder 4| is removably seated on the outer shouldered edge of the flange I5 so that there is provided between the two cylinders the elongated combustion chamber 43 aligned with and constituting an extension of the underlying fuel space I9. centric, spaced, perforated sheet metal cylinders 45 and 4'! are likewise removably seated on the shouldered edges of the flanges 21 and 29 respectively, providing between them the combustion chamber 49' bearing a relation to the outer fuel space 25 similar to that of the combustion chamber 43 to the fuel space I9. It will be understood that the perforations in the sheet metal cylinders are distributed throughout substantial ly the entire surface thereof, a small perforated area only being shown in Fig. 2. It will also be understood that these perforations may be of any shape, size or arrangement to provide suitable air admission openings for the combustion chambers.

A removable cover plate 5I is provided with its edges resting upon the tops of the sheet metal cylinders 4| and 41 to close the top of the annular air space therebetween, and a disc-shaped closure plate 53 with its edges resting on the upper edges of the cylinder 39 is similarly pro vided to close the top of the central air chamber, leaving, however, annular openings in the tops of the two combustion chambers 43 and 49 for the escape of the products of combustion. The closure plates 5I and 53, if desired, maybe provided with one or more apertures to permit the partial escape of air therethrough.

To render the burner effective for either liquid or gaseous fuel, the bottom of the combustion chamber 43 is separated from the top of the fuel space by a wall or partition in the form of a plate 55, and the combustion chamber 49 from the fuel space 25 by a plate 57, the plate 55 being provided with a series of restricted orifices 55 or their equivalent, and the plate 51 with a series of orifices 6|. The size, number and arrangement of these orifices may be varied but is preferably such that, while permitting the passage from the fuel space to the combustion chamber of either the gaseous fuel or of vaporized liquid fuel, the burning thereof is confined to the combustion space, and the flow of the gas or vapor is sufficiently restricted to cause a substantially even distribution thereof as it circulates throughout the fuel spaces and a substantially uniform combustion throughout both combustion chambers, whether supplied with gas through the pipe 3I or with liquid fuel through the pipe 2|.

The plate 55 is annular in shape and may be conveniently provided through a flanged extension of the cover plate 35, the outer edge of which is shouldered to fit closely to the inner walls of the upright flange I5, so as to prevent the passage of gas to the combustion chamberfrom the fuel space except through the orifices 59. The plate 51 is similarly annular in form, with its edges shouldered to fit upon the flanges 21 and 29 to Conclose the combustion chamber 49 to the fuel space except through the orifices 6 I.

It will be observed that the gas supply pipe entersthe burner above the bottom of the outer fuel groove 25 so that, if during the starting of the burner liquid fuel is admitted to the vaporizing space and allowed to pass over the lip l'l, liquid fuel may enter both fuel grooves and a shallow body of liquid fuel may gather in the bottom of said grooves and be retained therein until vaporized without interference with the free, concurrent admission of gaseous fuel to the fuel grooves and the combustion chambers from said fuel supply pipe.

While we have herein described for purposes of illustration one specific embodiment of the invention and one particular application thereof, it is to be understood that extensive deviations from and changes in the illustrated form may be made and applications thereof other than herein illustrated may be utilized, all without departing from the spirit of the invention.

While the oil supply is herein shown as delivered to the inner fuel groove and the gas supply to the outer fuel groove, our invention as to the delivery of the liquid fuel and the gas contemplates the delivery of the two fuels at any point, or points, which may be suited to the construction of the particular burner to which the invention is applied.

We claim:

1. A burner comprising an annular trough body having a central opening therethrough and having a low, uninterrupted dividing wall extending entirely around the trough body and forming inner and outer channels, a fuel supply means communicating with the inner channel, an annular baffle member having a base fitting within the opening through the trough and having a flange overlying the inner channel in closely spaced relation to the dividing wall to form a narrow opening therebetween, a foraminate chimney erected on the peripheral edge of the flange, and a second ioraminate chimney erected at the outer side of the trough.

2. A burner comprising an annular trough body having a central opening therethrough and having a low, uninterrupted dividing wall extending entirely around the trough body and forming inner and outer channels, the bottom of the outer channel being of at least the height of the inner channel, a fuel supply means communicating with the inner channel, an annular bafiie member having a base fitting within the opening through the trough and having a flange overlying the inner channel in closely spaced relation to the dividing wall to form a narrow opening therebetween, a foraminate chimney erected on the peripheral edge of the flange, and a second foraminate chimney erected at the outer side of the trough.

3. A burner comprising an annular trough body having a central opening therethrough and having a. low, uninterrupted dividing wall extending entirely around the trough body and forming inner and outer channels, a fuel supply means communicating with the inner channel, an annular baffle member having a base fitting within the opening through the trough and having a flange overlying the inner channel in closely spaced relation to the dividing wall to form a narrow continuous annular opening therebetween, a foraminate chimney erected on the peripheral edge of the flange, and a second foraminate chimney erected at the outer side of the trough.

4. A burner comprising an annular trough body having a central opening therethrough and having a low, uninterrupted dividing wall extending entirely around the trough body and forming inner and outer channels, a fuel supply means communicating with the inner channel from below to enable a controlled level to be established therein, an annular baifle member having a base fitting within the opening through the trough and having a flange overlying the inner channel in closely spaced relation to the dividing wall to form a narrow opening therebetween, a foraminate chimney erected on the peripheral edge of the flange, and a second foraminated chimney erected at the outer side of the trough.

RALLSTON M. SHERMAN. FREDERICK F. NEUMANN. 

